Logo link to homepage

Report on Sheveluch (Russia) — August 2005


Sheveluch

Bulletin of the Global Volcanism Network, vol. 30, no. 8 (August 2005)
Managing Editor: Richard Wunderman.

Sheveluch (Russia) 22 September eruption generated a substantial pyroclastic flow

Please cite this report as:

Global Volcanism Program, 2005. Report on Sheveluch (Russia) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 30:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200508-300270



Sheveluch

Russia

56.653°N, 161.36°E; summit elev. 3283 m

All times are local (unless otherwise noted)


From March 2005 until July 2005, the lava dome at Shiveluch continued to grow and ash-and-gas plumes and gas-and-steam plumes were frequent (BGVN 30:06). The alert level was at Orange.

On 7 July, the Russian News and Information Agency (RIA Novosti) reported that Shiveluch was producing pyroclastic flows and ash plumes rising to 5 km altitude. On 8 July, Kamchatka Volcanic Eruptions Response Team (KVERT) raised the alert level from Orange to Red, the highest level. Video footage taken the same day showed weak gas-and-steam plumes rising to ~ 5 km altitude. On 9 July, ash-and-gas plumes rose to 3 km altitude and the alert level was reduced to Orange. Ash plumes extended 27 km SW of the volcano during July 11-12.

Through July and August, the lava dome continued to grow and Shiveluch remained at alert level Orange. On 15 July, RIA Novosti reported that "[m]assive ash emissions from Shiveluch...are posing danger to nearby towns and villages. The Federal Earthquake Prediction Center's Kamchatka branch said ash storms, as well as mudflows from Shiveluch's slopes, could be dangerous for nearby settlements . . .. [T]he volcano began emitting massive ash clouds. Gas, ash, and magmatic material . . . are barreling down the slope . . .. The ash cloud has spread more than 700 kilometers to the [W] of the volcano, covering the peninsula and the nearby Sea of Okhotsk with a nearly 150-kilometer-wide strip."

On 19 July KVERT reported that a gas-steam plume extended 30 km SW from the volcano on 18 July and a gas-steam plume up to 3.5 km altitude was observed on 19 July. On 19 July, 23 July, and during 5-12 August, satellite data from the USA and Russia indicated a persistent 1 to 7 pixel thermal anomaly at the dome. On 23 July and 6 August, incandescence was observed at the lava dome. Fumarolic activity was visible on 6 August.

During 19-26 August, about ten shallow earthquakes were recorded, and a larger thermal anomaly was visible on satellite imagery. On 19 August a new viscous lava flow was emitted from the lava dome and continued to flow during 26 August to 9 September. Several ash plumes reached ~ 5.5 km altitude.

On 5 September, an ash plume rose to ~ 4 km altitude. On 8 September, a hot avalanche was accompanied by an ash plume that rose to a height of ~ 3.5 km altitude. The large thermal anomaly continued during the first week of September. On 7 September RIA Novosti reported that Shiveluch "is spewing gas and ash to heights of up to 5,000 feet [1.5 km]". On 16 September KVERT reported that the dome was continuing to grow and that viscous lava continued to flow from the dome. Incandescence at the lava dome was observed on 13 September. Gas-steam plumes up to 3.5 km altitude and a large thermal anomaly were registered all week.

On 22 September KVERT raised the alert level to Red, the highest level, and reported that according to seismic data, at 05:15 UTC on 22 September, a paroxysmal eruption began. Ash plumes reached a height about 7.5 km altitude, and ash fall was noted from 06:00 until 08:00 UTC on 22 September by seismologists working about 9 km SW of the volcano.

KVERT reported, based on US and Russian satellite data, an ash cloud with a diameter of ~ 20 km located ~ 90 km to the NW of the volcano and, based on Russian satellite data, an ash cloud with a diameter of ~ 15 km located ~ 20 km to the SSE at about 3 km altitude. Ash fall was observed in Klyuchi on the night of 22 September. According to visual data, a new pyroclastic flow extended 10-15 km.

Geological Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

Information Contacts: Olga A. Girina, Kamchatka Volcanic Eruptions Response Team (KVERT), a cooperative program of the Institute of Volcanic Geology and Geochemistry, Far East Division, Russian Academy of Sciences, Piip Ave. 9, Petropavlovsk-Kamchatsky, 683006, Russia, the Kamchatka Experimental and Methodical Seismological Department (KEMSD), GS RAS (Russia), and the Alaska Volcano Observatory (USA); Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA (URL: http://www.avo.alaska.edu/), the Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA, and the Alaska Division of Geological and Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA.